Authorities have confirmed that 12 people have died in flash flooding that swept away two vehicles in a town on the Utah-Arizona border.

Sgt. Brock Bentley of the Washington County Sheriff's Office in Utah confirmed Tuesday that three additional bodies have been found. One person remains missing in the floodwaters, while three children survived.

The wall of water washed the vehicles several hundred yards downstream Monday afternoon. Authorities say the victims are as young as 4 years old. It's unclear if they're all from the same family.